Just as a point of reference, 1 billion gallons is about 23.8 million barrels. This represents about a 1 1/2 days or US oil use.
I only use ~5 gal of Diesel most weeks. All I need is ~250gal of inexpensive Diesel/year. I can take delivery 2x per year and avoid going to the “gas” station.
Ummm, for a start-up to grab 0.5% of the entire US oil market in under two decades is amazing (if they hit their goal and your numbers are correct). On top of that, if they have that amazing success, hundreds of others will come along to try to copy it. I could be wondrous news...
but there are always those who disdained the invention of the automobile, because it couldn't do 90 mph and cost less than $5 in its first decade of production.